A state of moral or artistic decline or deterioration; decay
Decadance is an extended play by Japanese band m.o.v.e, released on September 10, 2003.
A falling away; decay; deterioration; declension. "The old castle, where the family lived in their decadence."
the state of being degenerate in mental or moral qualities
The word decadence, which at first meant simply in an abstract sense, is now most often used to refer to a perceived decay in standards, morals, dignity, religious faith, honor, discipline, or skill at governing among the members of the elite of a very large social structure, such as an empire or nation state. By extension, it may refer to a decline in art, literature, science, technology, and work ethics, or (very loosely) to self-indulgent behavior.